Squamous cell carcinoma in an umbilical cyst: a clinical image

A 49-year-old woman presented with a chronic, painful umbilical mass refractory to antibiotics and incision and drainage, ultimately diagnosed as well-differentiated squamous cell carcinoma (SCC) with positive margins. Imaging revealed an abnormal left inguinal lymph node, and biopsy confirmed metastatic disease. She underwent wide local excision with abdominal wall reconstruction and completion inguinal lymphadenectomy, which demonstrated extranodal extension in 2 of 10 nodes. Adjuvant radiotherapy was administered to the left groin, but surveillance imaging five months later showed progression to retroperitoneal and periaortic lymphadenopathy. She is currently receiving cemiplimab immunotherapy, highlighting the importance of multimodal management in treating rare primary abdominal wall SCC. As much of the literature and prior reports focus on cutaneous SCC, this case provides a unique insight into the diagnosis, treatment, and future of care in aggressive metastatic non-cutaneous primary SCC.